People gather at a rally honoring Trayvon Martin at Union Square in New York City on July 14. / Mario Tama, Getty Images

by Natalie DiBlasio, USA TODAY

by Natalie DiBlasio, USA TODAY

Trayvon Martin's would-be 19th birthday is marked Wednesday by day three of jury selection in a case that puts a spotlight back on Florida's "stand your ground" self-defense law.

Michael Dunn, 47, is charged with first-degree murder in the shooting of unarmed 17-year-old Jordan Davis during a dispute over loud music in November 2012.

Dunn, who is white, said he feared for his life and was acting in self-defense when he fired into an SUV containing four black teenagers, killing Jordan Davis, in Jacksonville.

George Zimmerman fatally shot Trayvon, also an unarmed black teen, in Sanford, Fla., in 2012. Zimmerman, who was acquitted, was prosecuted by Jacksonville's State Attorney Angela Corey, who also is prosecuting the Dunn case.

Sybrina Fulton, the mother of Trayvon, has advocated for a change in the "stand your ground" law since her son's death. "We need to do something about this law when our kids cannot feel safe in their own community," she said.

Early Wednesday, Fulton posted an image on Twitter of Trayvon's face on an American flag with the words "Happy 19th Birthday Trayvon."

Other users sent birthday wishes to Trayvon using #HoodiesUp and #NeverForget.

Zimmerman is also back in the news after an announcement Wednesday by Celebrity Boxing that he will box rapper DMX in March.

However, DMX's representation Domenik Nati has said: "The boxing match between George Zimmerman and DMX is not officially confirmed. DMX has promised to "beat his a--", but no contract or paperwork has been signed or agreed to yet."

Feldman, owner of Celebrity Boxing, said he had received 15,000 inquiries from people interested in fighting George Zimmerman since the fight was first advertised. "America wants to see this guy get his a-- kicked," Feldman said. "Everyone wants to see him lose."

Feldman said he heard from politicians, reality stars and television stars who all wanted to get in on the fight. "I am not here to hurt anybody," he said. "It's all about the show."